If you think that this file contains a virus or another malware, please download a virus scanner.
If siinst_2.exe is using too much CPU or too much memory in your system, it is possible that your file has been infected with a virus. Installing an antivirus is recommended.
Not all processes can be uninstalled without the help of a 3rd party tool, especially malware. To see if it can be uninstalled, first go to Start > Control Panel > Add/Remove programs and select Software Informer from the list to remove the process siinst_2.exe from your computer.
You may try contacting Informer Technologies, Inc., the developer of siinst_2.exe and ask for more information.